A restricted keyway solves exactly one problem, and it solves it completely. Blanks are not sold commercially, so nobody can quietly cut a copy. Consequently every key in circulation is one you authorised.
Why uncontrolled copying matters
A standard key costs a few dollars to duplicate and takes two minutes. Consequently a departing employee, a contractor or a former tenant can retain access indefinitely without doing anything obviously wrong. Furthermore, you have no way to know it happened. Therefore key control is not about mistrust. It converts an unknowable into a documented list.
Restricted versus patented
Restricted means the blank is distribution-controlled. Meanwhile patented means the design itself is legally protected, so nobody can manufacture compatible blanks at all. Consequently patented systems offer stronger protection for the patent term. However, restricted systems cost less and cover most commercial needs.
How authorisation works in practice
You nominate who may request copies. Consequently a request from anyone else is refused, and each key issued is numbered against a holder.
The arithmetic
Restricted cylinders cost more than standard ones, and spares must be ordered rather than cut while you wait. However, compare that against rekeying a building every time someone leaves. Consequently for premises with any staff turnover, restricted keyways generally pay for themselves within a couple of years.
Combining with a master system
Restricted cylinders work inside a master key hierarchy exactly as standard ones do. Consequently you keep the convenience of masters while gaining control. Furthermore, it protects the master itself from being duplicated, which is the single biggest risk in any master system. Therefore pairing the two is usually right for premises that need both.
Questions we get about this
Can anyone copy a restricted key?
No. Blanks are distribution-controlled and copies need authorisation.
What is the difference from a patented key?
Patented designs are legally protected, so no compatible blanks exist.
Can we still have a master key?
Yes, and restriction protects the master from duplication.
How long do extra keys take?
They are ordered rather than cut on demand, so plan ahead.
Is it worth it for a small business?
If staff turn over, usually. Because it beats rekeying repeatedly.
